RNA polymerase II is an essential mRNA polyadenylation factor
RNA polymerase II is an essential mRNA polyadenylation factor
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DOI：
10.1038/25786
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发表时间：
1998-09-03
期刊：
影响因子：
64.8
通讯作者：
Manley, JL
中科院分区：
文献类型：
--
作者：
Hirose, Y;Manley, JL
在真核细胞中生产信使RNA是一个复杂的、多步骤的过程。3‘加工需要多种蛋白质因子，包括切割/多聚腺苷酸化特异性因子(CPSF)、切割刺激因子、两个切割因子和多聚(A)聚合酶(参考文献1、2)。这些蛋白质似乎对mRNA合成的其他步骤，如转录和剪接来说是不必要的，这些过程所需的因子被认为不是多腺苷化所必需的。尽管如此，这些反应可能是相互关联的，因此它们在体内可以有效地协调(3-9)。例如，RNA聚合酶II(RNAP II)最大亚单位(RNAP II)的CTD羧基末端结构域是体内有效剪接和聚腺苷酸化所必需的(8)，CPSF由转录因子TFIID带到启动子上，并在转录启动时转移到RNAP II(9)。这些发现表明，多聚腺苷化因子可以被RNAP II招募到RNA3‘-处理信号中，在那里它们从聚合酶解离并启动多腺苷化。在这里，我们给出了扩展这一模型的结果，表明在没有转录的情况下，RNAP II实际上是3‘体外加工所必需的。
Production of messenger RNA in eukaryotic cells is a complex, multistep process. mRNA polyadenylation, or 3' processing, requires several protein factors, including cleavage/polyadenylation-specificity factor (CPSF), cleavage-stimulation factor, two cleavage factors and poly(A) polymerase (reviewed in refs 1, 2). These proteins seem to be unnecessary for other steps in mRNA synthesis such as transcription and splicing, and factors required for these processes were not considered to be essential for polyadenylation. Nonetheless, these reactions may be linked so that they are effectively coordinated in vivo(3-9). For example, the CTD carboxy-terminal domain of the largest subunit of RNA polymerase II (RNAP II) is required for efficient splicing and polyadenylation in vivo(8), and CPSF is brought to a promoter by the transcription factor TFIID and transferred to RNAP II at the time of transcription initiation(9). These findings suggest that polyadenylation factors can be recruited to an RNA 3'-processing signal by RNAP II, where they dissociate from the polymerase and initiate polyadenylation. Here we present results that extend this model by showing that RNAP II is actually required, in the absence of transcription, for 3' processing in vitro.